28638932109 has 4 divisors (see below), whose sum is σ = 38185242816. Its totient is φ = 19092621404.

The previous prime is 28638932059. The next prime is 28638932143. The reversal of 28638932109 is 90123983682.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28638932109 - 2¹² = 28638928013 is a prime.

It is a super-2 number, since 2×28638932109² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28638932809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4773155349 + ... + 4773155354.

It is an arithmetic number, because the mean of its divisors is an integer number (9546310704).

Almost surely, 2^28638932109 is an apocalyptic number.

It is an amenable number.

28638932109 is a deficient number, since it is larger than the sum of its proper divisors (9546310707).

28638932109 is an equidigital number, since it uses as much as digits as its factorization.

28638932109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9546310706.

The product of its (nonzero) digits is 1119744, while the sum is 51.

The spelling of 28638932109 in words is "twenty-eight billion, six hundred thirty-eight million, nine hundred thirty-two thousand, one hundred nine".